Zinc Additive, Or Lack Of

[Shadetree]

Its that time of year again. It is time to get the old cars out, change the oil and grease them. Has anyone on this forum ever had actual damage to their flathead engine because of the lack of Zinc in the engine oil?

Shadetree

[ford1]

no but i do not use the new oils that say "for gasolene engines only" that oil has a red seal or badge on the container with those words in it, its for newer cars that have roller lifters so they dont need the zink to protect the flat lifter cams, racing oils and the oils made for deisels work well in flat tappet cams

[Ol' Ron]

NASCAR engines use a flat tappet cam. I plan on using a synthetic oil in the eco engime.

[Pete]

If you could just pour something in your engine that would increase longeviety, would you do it?
You can look up the kind of oil you want to use or check out on the internet.
It will tell you how much zinc/phosphorous is in each brand..Granted the numbers may not be super accurate but they will be in the ballpark.

One big thing most people don't realize is, zinc/phosphorous is not only for the cam, it is for rings and valve stems also...Anywhere there is hard metal to hard metal contact will benefit.

[Big Red 51]

Shade Tree, I don't want to find out. I use it in my '51 and used in the '54 and both engines seem to get better each run.
Don

[Bassman/NZ]

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ZDDP in the recommended doseage will not do any harm. Whether it will do any good is debatable. Flatheads ran for 16 or so years before the oil companies were pressured into adding ZDDP. This was because the new Caddy, Olds and hemis had much higher valve spring pressures than the old flatties, and started wearing prematurely.

[fourtydlx]

Oil co.s had to remove zink because of it cut down on the life of cat. converters, I add it to all my eng. zddp, cheaper than cam,but as stated you can use racing oil or diesel. Just my observations.

[paul2748]

A fact - 1980 oil (Pennzoil 10/40) had 547 PPM of Phosphorus and 716 PPM on zinc. The new Rotella has 1100 ppm of Zinc (Old was 1276). I have seen studies on the internet by indy labs that show in excess of 1100 for 10/40 and 20/50 (Dino oil).

I agree with the statement on racing oil (so I have heard) but until some one comes up with a study showing the diesel oil is detrimental I will use it

Supposedly a straight 40 weight is around the same, but I have not seen a study with straight 40 weight.

[Ol' Ron]

What about Mobil #1? 5-30

[makemc]

on the inside of the glove box door on my 46 coupe, there is
a sticker that says for summer use 30 wt. for winter use 10 wt.
did they make a 10 wt oil back then. I know they did'nt make
multi wt back then

[V8 Bob]

Originally Posted by Jeff/Illinois

It should be understood, that using diesel engine motor oil in a gasoline engine is really not a very good idea. They are two completely different animals. The diesel oil does not have the same additives and detergents that gasoline engine oil does, they are designed to do two completely different things.

CJ rated oil in a gasoline engine,,,,no way I would do that.

OR, racing engine oil in a daily driver, also a bad idea. Racing oil is meant to be changed after a night at the drag strip. Not for a daily driver. Racing oil does not have the detergents and additives you need, neither does the diesel oil.

Buy your favorite modern gasoline rated engine oil. Add a can of ZDDP if that makes you happy (don't really need it in a flathead Ford design engine, this subject has been beat to death) and go out and drive your car and forget about it.

I've done a lot of research, and agree using diesel oil is not the best for gasoline engines, and for the reasons posted above.

However, there is at least one racing oil that can be used on the street, and that's Valvoline VR1 and synthetic VR1. (NOT the Specialty Racing "Not Street Legal" oil). It comes in several straight and multi-vis weights, is found in most auto parts stores, and is priced right. The 10W30 I use sometimes has to be ordered, but gets to the store the next day. I find this a much better alternative vs adding a $9 bottle of ZDDP to standard SM oil. Overkill in my flatheads, maybe, but needed in older HP OHV engines, and very cost effective peace of mind. IMO

[FL&WVMIKE]

Bite the bullet and use synthetic oil in your flatheads. They, probably, do not really need the zinc.
Synthetic oil is so friction free, that you can't break your engine in, with it.
MIKE

[Roger/Sacramento]

When I get mine on the road I will use straight 30 for the first 1,000 miles and change to a blend thereafter. Wonder how much oil will be next year?

[Ol' Ron]

I know several people that have run a synthetic with no problem, yet. will use 5-30

[paul2748]

Originally Posted by Ol' Ron

I know several people that have run a synthetic with no problem, yet. will use 5-30

If it says for gasoline engines only, I would not use it. Usually these lower weight oils are designed for late model roller engines.